Method for treating wool



Patented Dec. 22, 1953 No Drawing. Application July 9,1951,

seaiN 235,907

Qlaims priority, application A ri 27, 1949' This application is acontinuation=in=part of my application'ser." No, "156,489, filed April17, 1950, and now abandoned.

This invention relates to a method of treating wool with an aqueoussolution containing active chlorine as well as to wool treated by thismethod.

The chlorination of WQOI, that is to say the treatment of wool withchlorine or with aqueous solutions containing aotive chlorine, such as qou t qns of ehle e e Qt yp c r c or salts thereet ha e n rec mmen ed forre d t i tan t sh inka e an t -v The rapid r a ti ty 9f ch ori towa sW99 i a mfu t at i easil leads to l ee ir e ula ties in thechlo'rinating action.

Proposals for overcoming this disadvantage have already been made. Inthe U. S. Patent No. 2,144,824 it has been proposed to retard the actionof chlorine or hypochlorites on wool by the addi: tion of ammonia orcompounds containing amino or iminogroups, more especially thedegradation products of proteins. Furthermore, U. S. Patent No.2,395,724 suggests the application to the wool, before the chlorinationtreatment, of a melamine,- formaldehyde condensation product in order toprotect the wool from injury.

The present invention is based on the ob-. servation that the foregoingdisadvantage can be remedied more effectively and simply by con:vducting the chlorination in the presence of a water-soluble methylolcompound of melamine, or in the presence of water-soluble alkylated,particularly methylated methylol compound of melamine.

By water-soluble methylol compounds of melamine, which may be used for.the present in? vention there are understood melamine-formaldehydecondensation products soluble in water at least with addition of somehydrochloric acid and obtainable by reacting melamine .with formaldehydein an alkaline medium as well as alkylated methylol compounds ofmelamine which are soluble in water at least with addition of somehydrochloric acid and which may be obtained known manner by condensingmelamine, formaldehyde and the alcohol, particularly methanol, or byetherifying a methylol compound of melamine, both reactions z beingconducted in the presence of an acid,

The present v observation that the aforesaid d ne replaced, h .51 re ultb math-r191 ewe pound or a ky-l e eela ly meth ed methyl?! tem s-eds e non also bases .0 the Whee ie! containing at least two. amino groups andbeing 'free from other reactive substituents, such as formoguanamine (4diamino-lfifi-triagine), aoetog lanamine' (4.6 e diamino 2-methyl-"l.3.5 -f triazine benzoguanamine(4.6-.diamino-2-phenyl-l.3.5.-triazine) or the like, or'by alkyl ethers,

particularly the dimethyl ether, of dimethylol urea, All these comp ndsmust be soluble in water at least with addition of some hydrochloricacid, and they may be obtained in an analogous ethers ofdimethylol urea,p

By'this' process" the reaction of the chlorine with the Wool is retardedin such a way that local underor 've chlor'ination is prevented to avery considerable extent. Wool treated by the process of this intentionexhibit whenw'ashed, t e des d resis i e to shr n a n f n and also a'icons erably better". resistance to changes in shape-than metal whichhas been treat-j ed, rar'exam m, with Javelle water alone.

These condensation products may be added to the treatment bath directlyor in the form of aqu s s ut en in a te ea es i has e under advan e t ime se he WOQl t in an a u ou se t n f e ee d ee t ee rqdr uct and thento add active chlorine to the bath.

According to the present invention, the treatment of the wool is pr ieably carried out a 0W temperatures, i. e. without that the treatmentbath is heated at any stage of the process. -It has proved ,to beappropriate to keep the temperature "of the bath at about 16? C. duringthe whole treatment. According to the quantity and the kind of methylolcompound used in the bath and according to'the quantity of activechlorine present in the bath, the chlorination can also be carried outat a highertemperalture at least to Wards the end of the treatment, forinstance at about 60 0'. Such aIh'ethod of working has I usin 3% methyat Proved t h ueeessm {by cpns eeset e tra e am lam e a d farm a d yde.The och-1o nation {at r sed temperathis? al ews reaction and e chlorinewhich is present in the bath. The process is preferably so conductedthat the wool is first brought into an aqueous solution of the methylolcompound in the cold, i. e. below or at about room temperature,whereupon the chlorinating agent for instance in the form of an aqueoussodium hypochlorite solution is added to the solution, if necessary inseveral portions, and that after addition of the last portion of thechlorinating agent the temperature of the bath is raised to above roomtemperature, preferably to about 60 0., thus terminating thechlorination of the wool. The process may also be performed in such away that the wool is brought into a liquor containing the whole quantityofthe chlorinating agent and the methylol compound and heating theliquor towards the end of the treatment.

Example 4 6'? parts of wool yarn are treated for about 10 minutes atabout 16 C. in a dyeing apparatus with a circulating bath which contains1000 parts of water, 2.67 parts of a methylated melamine- The followingexamples illustrate the invention, the parts and percentages being byweight:

Example 1 33 parts of wool yarn, after being wetted are treated forabout 30 minutes at about 16 C. while being gently worked, in a bathwhich contains in 1000 parts of water 2 parts of a methylated methylolcompound of melamine, 0.8 part of aqueous hydrochloric acid of 30 percent. strength, 0.6 part of sulphuric acid of 99 per cent. strength and0.8 part of active chlorine in the form of Javelle water. The yarn isthen rinsed, dechlorinated in the usual manner with sodium bisulphite,rinsed again, centrifuged and dried at about 70 C.

The wool so treated, as compared with wool which has been treated withJavelle water alone, exhibits the same resistance to felting but has afuller feel and a much improved resistance to change of shape whenwashed.

The methylated methylol compound of melamine used in this example may beprepared as follows: 40.3 parts of melamine are condensed in knownmanner under alkaline conditions at a raised temperature with 192 partsof aqueous formaldehyde solution of 37 per cent. strength, and theresulting condensation product is etherified after the addition of 157parts of methanol and concentrated hydrochloric acid. Afterneutralization with caustic soda solution volatile constituents aredistilled off until the mixture has a content of dry substance of'72-'75 per cent.

Example 2 Wool yarn is treated in the manner described in Example 1,except that the bath contains in 1000 parts of water 8 parts of the samemethylated methylol compound of melamine as is used in Example 1, 3.2parts of aqueous hydrochloric acid of 30 per cent. strength, 1.2 partsof sulphuric acid of 99 per cent. strength and 1.6 parts of activechlorine in the form of Javelle water. The yarn has properties similarto those of the goods treated as described in Example 1.

A similar procedure is followed when nonetherified methylol compounds ofmelamine are used, for example, a condensation product from 1 mol ofmelamine and about 31 mols of formaldehyde which has only limitedsolubility in water but unlimited solubility in water in the presence ofan acid.

Example 3 33 parts of wool yarn are treated for about 10 minutes atabout 16 C. in a dyeing apparatus with a circulating bath which containsin 1000 parts of water 0.2! part of the same methylated methylolcompound of melamine as used in Exformaldehyde condensation product and4 parts of aqueous hydrochloric acid of 30 per cent. strength. 0.67 partof active chlorine in the form of an aqueous sodium hypochloritesolution are then added to the circulating bath in five equal portionswithin about 40 minutes, the bath showing a temperature of 16-18 C.About 5 minutes after the addition of the last portion of the activechlorine, the temperature of the bath is raised to about 60 C. withinabout /2 hour and the treatment of the wool continued until the chlorineis practically entirely consumed. The wool is dechlorinated in the usualmanner by adding to the bath 4 parts of a commercial aqueous so diumbisulfite solution of about 40 per cent. strength. After rinsing anddrying, the yarn shows a good resistance to felting and shrinkage whenwashed.

Example 5 25 parts of a knitted woollen fabric are prewetted in anaqueous solution containing in 1000 parts 2 parts of an ion-free wettingagent, such as for instance of a water-soluble condensation product froman organic hydroxyl compound and ethylene oxide, whereupon the goods istreated in a reel vat for about 10 minutes at about 16 C. with a bathwhich contains 1000 parts of water, 0.5 part of the above-mentionedwetting agent, 0.5 part of the methylated melamine-formaldehydecondensation product used in Example 1 and 1.75 parts of aqueoushydrochloric acid of 30 per cent. strength. 0.25 part of active chlorinein the form of an aqueous sodium hypochlorite solution is 'then added tothe bath within about 40 minutes in five equal portions. Thereupon, thetemperature of the bath in pres ence of the knitted woollen fabric israised to about 00 C. within about '30 minutes. At this temperature, thetreatment of the wool is terminated within about a further 15 minutesand the knitted woollen fabric dechlorinated as indicated in Example 1,rinsed and dried.

In case the wool should still be dyed, it is appropriate to treat it,before dyeing or drying, respectively, with aqueous ammonia for thepurpose of neutralization.

The knitted wool fabric so treated exhibits a good resistance to feltingand shrinkage when washed.

Example 6 33 parts of well wetted wool yarn are treated with frequentmovement at 16 C. in a bath which contains in 1000 parts of water 0.6?part of the methylol-benzoguanamine obtained by the condensation of 1mol of benzoguanamine with about 4 mols of formaldehyde, 0.8 part ofactive chlorine in the form of Javelle liquor and 1.35

parts of hydrochloric acid of 30 per cent. strength. After 10 minutes aiurther-0$65 part of hydrochloric-acid of 30 per cent. strength isadded, whereupon the yarn is further treated for 50 minutes at 16 C. Inorder to remove the chlorine the yarn is then treated for 10 minutes at16C. in a bath containing, per litre, 5 cc. of asodium :bisulphitesolution of 40 per cent. strength. The yarn is then rinsed and dried atabout50-10 -.C.

Instead of the methylol-benzoguanamine there may be used with equalsuccess, for example, the methyl ether thereof, or a condensationproductof 1 molof acetoguanamine oral mol of formoguanamine with about 2-4 molsof formaldehyde or the methyl ether of such :a condensation product.

Similar results are obtained by using instead Uf 0.67 part, only about'OJ IG'TTD'ZTE f the icondensa'tion products mentionedabove.

Example 7 33 parts of wool yarn are treated for about 10 minutes atabout 16 C. in a dyeing apparatus having a circulating bath whichcontains 1000 parts of water, 0.26 part of the product of theetherification with methyl alcohol of a condensation product of 1 mol offormoguanamine with 3.5 to 4 mols of formaldehyde, and 2 parts of anaqueous solution of hydrochloric acid of 30 per cent. strength. To thecirculating bath there are then added in all 0.33 part of activechlorine in the form of a dilute solution of sodium hypochlorite in 5approximately equal portions at intervals of about minutes. After theaddition of the last portion the treatment of the wool yarn in thecirculating bath is continued for about 30 minutes longer at about 16C., and then 2 parts of an aqueous solution of sodium bisulphite ofabout 40 per cent. strength are added to the chlorination bath in orderto eliminate the chlorine, and then wool is after-treated in theresulting solution for about minutes.

Example 8 33 parts of wool yarn, after being previously wetted, aretreated for about 1 hour at about 16. C. in a bath containing 1000 partsof water, 2.67 parts of the dimethyl ether of dimethylol-urea. 0.8 partof active chlorine in the form of Javelle liquor and 2.0 parts ofaqueous hydrochloric acid of 30 per cent. strength, the goods beingoccasionally gently worked in the bath. The hydrochloric acid is addedto the bath in two porti0nS, the first portion being added when makingup the bath and amounting to 1.3 parts of aqueous hydrochloric acid of30 per cent. strength and the second portion being added 10 minutesafter the commencement of the treatment of the wool and amounting to 0.7part of aqueous hydrochloric acid of 30 per cent strength. After thetreatment the yarn is rinsed, dechlorinated in the usual manner withsodium bisulphite, centrifuged and dried at about 50-70 C.

The dimethyl ether of dimethylol-urea used above may, for example, beprepared as follows:

150 parts of dimethylol-urea are introduced in portions in the course of3 minutes into 1000 parts of methyl alcohol at about 50 C., whilestirring, and then 0.6 part of aqueous hydrochloric acid of 36 per cent.strength is added, whereupon after a further 4 minutes thedimethylol-urea dissolves leaving only a. small amount of insolublematerial. By the addition of 0.38 part of an aqueous solution of sodiumcarbonate the hydrochloric acid is neutralised, the solution is thenfiltered while aces-tie I 6 still warmnd 'the'fil-trateisleoncentratedzby dis;- ti-lling lofi about 7-50" parts of methylialcohol. By cooling the concentrate to about =8 0. and allowing it tostand the colourless dimethyl ether of dimethylol-urea crys'tallisesout, and is separated from the mother li'quor by filtration. In.- steadof the di-metliyl ether of dimethylol-urea used in "the above example,there may be fused with'equal success the diethyl ether ofdimethylol-urea; I

What I claim is:

' 1. A method of treating wool with an acidic aqueous solutioncontaining active-chlorine which gprocess-comprises conducting thetreatment in the presence of a water soluble methylol compound selectedfrom the grou consisting of methylol compounds of an aminotriazinecontainingat least two amino groups and being free from other reactivesubstituents, alkyl ethers of such methylol compounds and alkyl ethersof dimethylol urea, and thereafter removing the said methylolcompound byrinsing, and dechlorinating the wool.

2. A method of treating W001 with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble methylol compound of melamine, andthereafter removing the said methylol compound by rinsing, anddechlorinating the wool.

3. A method of treating wool with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble alkylated methylol compound of melamine, andthereafter removing the said methylol compound by rinsing, anddechlorinating the wool.

4. A method of treating wool with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble methylated methylol compound of melamine,and thereafter removing the said methylol compound by rinsing, anddechlorinating the wool.

5. A method of treating wool with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble methylol compound of an aminotriazinecontaining two NHz-groups and being free from other reactivesubstituents, and thereafter removing the said methylol compound byrinsing, and dechlorinating the wool.

6. A method of treating wool with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble alkylated methylol compound of anaminotriazine containing two NHz-groups and being free from otherreactive substituents, and thereafter removing the said methylolcompound by rinsing, and dechlorinating the wool.

7. A method of treatingwool with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble methylated methylol compound of anaminotriazine containing two NHz-groups and being free from otherreactive substituents, and thereafter removing the said methylolcompound by rinsing, and dechlorinating the wool.

8. A method of treating wool with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence, of a water-soluble alkyl ether of dimethylolurea, andthereafter removing the said methylol compound by rinsing, anddechlorinating the W001.

9. A method of treating wool with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble dimethyl ether of dimethylol urea, andthereafter removing the said methylol compound by rinsing, anddechiorinating the wool. 1

10. A method of treating W001 with an acidic aqueous solution containingactive chlorine which process comprises conducting the treatment in thepresence of a water-soluble diethyl ether of dimethylol urea, andthereafter removing the said methylol compound by rinsing, anddechlorinating the wool. V

V GEORG SULZER.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber

1. A METHOD OF TREATING WOOL WITH AN ACIDIC AQUEOUS SOLUTION CONTAININGACTIVE CHLORINE WHICH PROCESS COMPRISES CONDUCTING THE TREATMENT IN THEPRESENCE OF A WATER-SOLUBLE METHYLOL COMPOUND SELECTED FROM THE GROUPCONSISTING OF METHYLOL COMPOUNDS OF AN AMINOTRIAZINE CONTAINING AT LEASTTWO AMINO GROUPS AND BEING FREE FROM OTHER REACTIVE SUBSTITUENTS, ALKYLETAHERS OF SUCH METHYLOL COMPOUNDS AND ALKYL ETHERS OF DIMETHYLL UREA,AND THEREAFTER REMOVING THE SAID METHYLOL COMPOUND BY RINSING, ANDDECHLORINATING THE WOOL.